Michael Manganiello 9602d58865
misc: Add support for WEB_CONCURRENCY environment variable
The `WEB_CONCURRENCY` environment variable is a more common way to
configure the number of workers for Gunicorn [1] or other web servers.

This change maintains `GUNICORN_WORKERS` compatibility, while notifying
users that it is deprecated and should be replaced with
`WEB_CONCURRENCY`.

It would also allow us to replace Gunicorn with another web server in
the future without changing the variable name.

[1] https://docs.gunicorn.org/en/stable/settings.html#workers
2025-02-19 00:31:34 -03:00

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#!/usr/bin/env bash
set -o errexit # treat errors as fatal
set -o nounset # treat unset variables as an error
set -o pipefail # treat errors in pipes as fatal
shopt -s inherit_errexit # inherit errexit
# make it possible to disable the inotify watcher process
ENABLE_RESCAN_ON_FILESYSTEM_CHANGE="${ENABLE_RESCAN_ON_FILESYSTEM_CHANGE:="true"}"
# Set INIT_DEBUG to false if not set by docker env
# (this env var is currently undocumented and usually just needed for development purposes)
INIT_DEBUG="${INIT_DEBUG:="false"}"
# print debug log output if enabled
debug_log() {
if [[ ${INIT_DEBUG} == "true" ]]; then
echo "DEBUG: [init][$(date +"%Y-%m-%d %T")]" "${@}" || true
fi
}
info_log() {
echo "INFO: [init][$(date +"%Y-%m-%d %T")]" "${@}" || true
}
warn_log() {
echo "WARNING: [init][$(date +"%Y-%m-%d %T")]" "${@}" || true
}
error_log() {
echo "ERROR: [init][$(date +"%Y-%m-%d %T")]" "${@}" || true
exit 1
}
wait_for_gunicorn_socket() {
info_log "waiting for gunicorn socket file..."
while [[ ! -S /tmp/gunicorn.sock ]]; do
sleep 1
done
info_log "gunicorn socket file found"
}
# function that runs or main process and creates a corresponding PID file,
start_bin_gunicorn() {
# cleanup potentially leftover socket
rm /tmp/gunicorn.sock -f
# commands to start our main application and store its PID to check for crashes
info_log "starting gunicorn"
# TODO: Remove support for GUNICORN_WORKERS in future version.
if [[ -n ${GUNICORN_WORKERS-} ]]; then
warn_log "GUNICORN_WORKERS variable is deprecated, use WEB_CONCURRENCY instead"
: "${WEB_CONCURRENCY:=${GUNICORN_WORKERS}}"
fi
gunicorn \
--access-logfile - \
--error-logfile - \
--worker-class uvicorn.workers.UvicornWorker \
--bind=0.0.0.0:5000 \
--bind=unix:/tmp/gunicorn.sock \
--pid=/tmp/gunicorn.pid \
--forwarded-allow-ips="*" \
--workers "${WEB_CONCURRENCY:-2}" \
main:app &
}
# Commands to start nginx (handling PID creation internally)
start_bin_nginx() {
wait_for_gunicorn_socket
info_log "starting nginx"
if [[ ${EUID} -ne 0 ]]; then
nginx
else
# if container runs as root, drop permissions
nginx -g 'user romm;'
fi
}
start_bin_valkey-server() {
info_log "starting valkey-server"
# Check if /usr/local/etc/valkey/valkey.conf exists and use it if so
if [[ -f /usr/local/etc/valkey/valkey.conf ]]; then
valkey-server /usr/local/etc/valkey/valkey.conf &
else
valkey-server --dir /redis-data &
fi
VALKEY_PID=$!
echo "${VALKEY_PID}" >/tmp/valkey-server.pid
}
# function that runs our independent python scripts and creates corresponding PID files,
start_python() {
SCRIPT="${1}"
info_log "starting ${SCRIPT}.py"
python3 "${SCRIPT}.py" &
WATCHER_PID=$!
echo "${WATCHER_PID}" >"/tmp/${SCRIPT}.pid"
}
watchdog_process_pid() {
TYPE=$1
PROCESS=$2
if [[ -f "/tmp/${PROCESS}.pid" ]]; then
# check if the pid we last wrote to our state file is actually active
PID=$(cat "/tmp/${PROCESS}.pid") || true
if [[ -d "/proc/${PID}" ]]; then
debug_log "${PROCESS} still running, no need to start"
else
if [[ ${TYPE} == "bin" ]]; then
start_bin_"${PROCESS}"
elif [[ ${TYPE} == "python" ]]; then
start_python "${PROCESS}"
fi
fi
else
if [[ ${TYPE} == "bin" ]]; then
start_bin_"${PROCESS}"
elif [[ ${TYPE} == "python" ]]; then
start_python "${PROCESS}"
fi
fi
}
stop_process_pid() {
PROCESS=$1
if [[ -f "/tmp/${PROCESS}.pid" ]]; then
PID=$(cat "/tmp/${PROCESS}.pid") || true
if [[ -d "/proc/${PID}" ]]; then
info_log "stopping ${PROCESS}"
kill "${PID}" || true
# wait for process exit
while [[ -e "/proc/${PID}" ]]; do sleep 0.1; done
fi
fi
}
shutdown() {
# shutdown in reverse order
stop_process_pid scheduler
stop_process_pid worker
stop_process_pid watcher
stop_process_pid nginx
stop_process_pid gunicorn
stop_process_pid valkey-server
}
# switch to backend directory
cd /backend || { error_log "/backend directory doesn't seem to exist"; }
info_log "Starting up, please wait..."
# setup trap handler
exited=0
trap 'exited=1 && shutdown' SIGINT SIGTERM EXIT
# clear any leftover PID files
rm /tmp/*.pid -f
# function definition done, lets start our main loop
while ! ((exited)); do
# Start Valkey server if we dont have a corresponding PID file
# and REDIS_HOST is not set (which would mean we're using an external Redis/Valkey)
if [[ -z ${REDIS_HOST:=""} ]]; then
watchdog_process_pid bin valkey-server
fi
# Run needed database migrations on startup,
# but only if it was not successful since the last full docker container start
if [[ ${ALEMBIC_SUCCESS:="false"} == "false" ]]; then
if alembic upgrade head; then
debug_log "database schema migrations succeeded"
ALEMBIC_SUCCESS="true"
else
error_log "Something went horribly wrong with our database"
fi
else
debug_log "database schema already upgraded during current container lifecycle"
fi
# Start gunicorn if we dont have a corresponding PID file
watchdog_process_pid bin gunicorn
# Start nginx if we dont have a corresponding PID file
watchdog_process_pid bin nginx
# only start the watcher.py if we actually want to use the rescan on fs change feature
if [[ ${ENABLE_RESCAN_ON_FILESYSTEM_CHANGE} == "true" ]]; then
# Start watcher if we dont have a corresponding PID file
watchdog_process_pid python watcher
fi
# Start background worker processes
debug_log "Starting worker and scheduler"
# Start worker if we dont have a corresponding PID file
watchdog_process_pid python worker
# Start scheduler if we dont have a corresponding PID file
watchdog_process_pid python scheduler
# check for died processes every 5 seconds
sleep 5
done